ApoER2 is expressed on PV-interneurons. A, Images of CA1 region of the hippocampus probed with an ApoER2 antibody in the absence (left panel) and presence (right panel) of an ApoER2 blocking peptide which left only background staining. B, C, D, Confocal images showing the expression of ApoER2 (left), PV (middle left), GAD67 (middle right), and colocalization of the markers (right) in the somatosensory cortex (B) hippocampus (C), and inferior colliculus (D) of WT mice. Higher magnification of merged images (far right). Scale bar: 100 μm.